From New Scientist:

[quote author=“Précis”]Solar system could go haywire before the Sun dies
Two new studies suggest a collision with Mercury or Mars could doom the Earth long before the Sun becomes a red giant in about 5 billion years. The studies suggest that the planets’ orbits may not be stable beyond another 40 million years. Predicting what will happen is extremely challenging because so many bodies are involved. Even small errors today can translate into huge uncertainties in the future. Because of this, astronomers are only able to say that the solar system will remain stable for the next 40 million years.

Now, new calculations suggest that there is a 1 to 2% chance that Mercury’s orbit will get seriously perturbed within 5 billion years, destabilising the whole inner solar system and leading to a catastrophic collision between Earth and either Mercury or Mars. According to co-author Gregory Laughlin, a collision with Mars would leave the Earth as hot as “a red giant star” for a thousand years.

In the other study, Jacques Laskar of the Paris Observatory, ran 1001 computer simulations of the solar system, with slightly different starting conditions, in a method called ensemble modelling. Again, in 1 to 2% of cases, Mercury’s orbit became very elongated due to the gravitational pull of Jupiter, increasing its interactions with Venus, Mars and Earth and possibly throwing the whole solar system into disarray.

“Once Mercury’s eccentricity gets up above about 0.6, ” Laughlin told New Scientist, “[...] then all bets are off

Let us hope that given the amount of time in either of the first scenarios, we’ve already been exploring space even beyond our solar system.  Better yet, that knowing what kinds of events could and probably will happen if left to natural inclinations, we have become clever enough in our science and technology advances, that we can literally haul some of our planets into more stable or suitable positions in order to save them.

It’d be pretty cool to stand at the exact spot where the two collided. I mean, you’d be squished to death, but what a way to go.

Just imagine how hard you’d rule in Heaven!

“How’d you die?”

“I was run over by a bus.”

“Oh, you were hit by a bus? That’s cool, I guess. I was hit by a f*cking planet!”

(Presumably, in Heaven, when you try to cuss, you get censored.)

Stargazer - 23 April 2008 12:50 PM

“Oh, you were hit by a bus? That’s cool, I guess. I was hit by a f*cking planet!”

Isn’t the same true of anyone who fell off a cliff?

hulitoons - 23 April 2008 11:24 AM

Let us hope that given the amount of time in either of the first scenarios, we’ve already been exploring space even beyond our solar system.

I’d say that all of the posited scenarios are many orders of magnitude more probable than us being around to be affected by them… Even if we hasdn’t gone extinct looooooooooooooong before then (which is to all intents and purposes a certainty), even the shortest horizon imagined (40m years) is time enough that we’d be unrecognizeable. Go back 40m years and you’ll find our common ancestor with lemurs, more or less - think what that means for the future.

My money’s on a world ruled by ratmen.

David B. - 23 April 2008 12:54 PM

Isn’t the same true of anyone who fell off a cliff?

No, in that situation, the planet is hit by them. They just take the brunt of the impact.

Special Relativity disagrees.

Yeah, that’s why it’s “special”. But, it did come in first place at the Special Olympics last year, and I was cheering so hard for Relativity the whole time!

outeast - 23 April 2008 01:07 PM

..................(40m years) is time enough that we’d be unrecognizeable. Go back 40m years and you’ll find our common ancestor with lemurs, more or less - think what that means for the future.

My money’s on a world ruled by ratmen.

I’ve actually enjoyed contemplating what our million-year-old offspring would look like given evolutionary changes.  Unrecognizable is an apt description I’m sure, but I do hope we don’t favor rats (even though I adore the domestic variety)....perhaps something luminescent?

hulitoons - 23 April 2008 01:54 PM

outeast - 23 April 2008 01:07 PM

..................(40m years) is time enough that we’d be unrecognizeable. Go back 40m years and you’ll find our common ancestor with lemurs, more or less - think what that means for the future.

My money’s on a world ruled by ratmen.

I’ve actually enjoyed contemplating what our million-year-old offspring would look like given evolutionary changes.  Unrecognizable is an apt description I’m sure, but I do hope we don’t favor rats (even though I adore the domestic variety)....perhaps something luminescent?

Jellyfish???

David B. - 23 April 2008 09:37 AM

And what are our governments doing to address this threat? Nothing! Pfft, your tax dollars at work!

Um, isn’t that our tax dollars NOT at work?